Loop Telecom and Essar which have been under CBI scanner in 2G spectrum allocation case, have challenged the Delhi high court on Wednesday.

The plea of Loop, Essar is that they should not be investigated by the CBI as they have not been booked under the Prevention of Corruption Act. A division bench, comprising Justice B D Ahmed and Justice V K Jain is likely to hear their plea on Thursday.

Ruias, the promoters of Essar Group and the Khaitans have figured in the third chargesheet filed by the CBI on December 12. They face accusation of creating Loop for getting more spectrum.

According to the agency Essar group floated Loop Telecom flouting telecom guidelines. Essar holds sizeable shares in the existing operating company Vodafone.

Essar Group’s Ravi Ruia, son Anshuman Ruia and Ruia brothers’ sister Kiran Khaitan and her husband IP Khaitan were also named in the new chargesheet.